# Development of a New Method for the Absolute Quantification of Selenoproteins in Chicken Serum by Heteroatom-Tagged Proteomics

## TL;DR

A new method for measuring selenoproteins in chicken serum is developed using tagged proteomics to better understand selenium levels in poultry.

## Contribution

A novel analytical method for absolute quantification of selenoproteins and metabolites in chicken serum using heteroatom-tagged proteomics.

## Key findings

- Most selenium in chicken serum is found as selenoprotein P.
- Selenoprotein W, selenometabolites, glutathione peroxidase, and selenoalbumin were also identified.
- The method can help optimize selenium supplementation in poultry.

## Abstract

Selenium (Se) is an essential trace element for chickens
that develops,
through selenoproteins, important physiological functions. Although
selenogen expression and Western blot analyses provided valuable information,
there is a lack of information about the serum selenoproteome and
quantitative data. In this work, we developed a new analytical method
for the absolute quantification of selenoproteins and total selenometabolites
in chicken serum using heteroatom-tagged proteomics, based on chromatographic
separation and Se detection as a “tag” in an atomic
detector. The approach was combined with bottom-up proteomics using
liquid chromatography coupled to organic mass spectrometry after a
tryptic digestion, and selenoprotein W was identified in chicken serum.
Our results indicated that the majority of chicken serum Se is as
selenoprotein P, followed by selenoprotein W, selenometabolites, glutathione
peroxidase, and selenoalbumin. The approach could be a valuable tool
to assess Se and selenoprotein status for the optimisation of supplementation
strategies to meet the Se requirements of poultry.